SOLUTION: x squared - 10x + 9 = 0 I subtracted 9 on both sides. x squared - 10x = -9 and I'm lost from here. Can someone please help me?

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: x squared - 10x + 9 = 0 I subtracted 9 on both sides. x squared - 10x = -9 and I'm lost from here. Can someone please help me?      Log On


   

Question 194491: x squared - 10x + 9 = 0
I subtracted 9 on both sides.
x squared - 10x = -9
and I'm lost from here. Can someone please help me?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Note: because this is a quadratic and there are two terms that involve "x", you can't isolate "x" using linear techniques.


x%5E2-10x%2B9=0 Start with the given equation.


Notice we have a quadratic equation in the form of ax%5E2%2Bbx%2Bc where a=1, b=-10, and c=9


Let's use the quadratic formula to solve for x


x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29 Start with the quadratic formula


x+=+%28-%28-10%29+%2B-+sqrt%28+%28-10%29%5E2-4%281%29%289%29+%29%29%2F%282%281%29%29 Plug in a=1, b=-10, and c=9


x+=+%2810+%2B-+sqrt%28+%28-10%29%5E2-4%281%29%289%29+%29%29%2F%282%281%29%29 Negate -10 to get 10.


x+=+%2810+%2B-+sqrt%28+100-4%281%29%289%29+%29%29%2F%282%281%29%29 Square -10 to get 100.


x+=+%2810+%2B-+sqrt%28+100-36+%29%29%2F%282%281%29%29 Multiply 4%281%29%289%29 to get 36


x+=+%2810+%2B-+sqrt%28+64+%29%29%2F%282%281%29%29 Subtract 36 from 100 to get 64


x+=+%2810+%2B-+sqrt%28+64+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%2810+%2B-+8%29%2F%282%29 Take the square root of 64 to get 8.


x+=+%2810+%2B+8%29%2F%282%29 or x+=+%2810+-+8%29%2F%282%29 Break up the expression.


x+=+%2818%29%2F%282%29 or x+=++%282%29%2F%282%29 Combine like terms.


x+=+9 or x+=+1 Simplify.


So the answers are x+=+9 or x+=+1